Renal cell carcinoma is a type of kidney cancer that originates in the lining of the proximal convoluted tubule, the very small tubes in the kidney that transport GF (glomerular filtrate) from the glomerulus to the descending limb of the nephron. RCC is the most common type of kidney cancer in adults, responsible for approximately 80% of cases.
It has been described as being among the most lethal of all the urological cancers. Initial treatment is most commonly a radical or partial nephrectomy and remains the mainstay of curative treatment. Where the tumour is confined to the renal parenchyma, the 5-year survival rate is 60-70%, but this is lowered considerably where metastases have spread. It is relatively resistant to radiation therapy and chemotherapy, although some cases respond to immunotherapy.
Other symptoms that can occur with this disease:
The greatest risk factors for RCC are lifestyle related - smoking, obesity and hypertension have been estimated to account to 50% of cases. Occupational exposure to some chemicals, such as asbestos, cadmium, lead, chlorinated solvents, petrochemicals and PAH (polycyclic aromatic hydrocarbon), has been examined by multiple studies with inconclusive results. Another suspected risk factor is the long term use of non-steroidal anti-inflammatory drugs (NSAIDS).
Finally, studies have found that women who have had a hysterectomy are at more than double the risk of developing RCC than those who have not.
Hereditary factors have a minor impact on individual susceptibility with immediate relatives of people with RCC having a two to fourfold increased risk of developing the condition.
Diagnosis of RCC usually occurs in people aged 40 years or older, with a peak between 50 to 80 years of age.
The likelyhood of developing Renal Cancer is higher among males, in comparision to women.
The following may increase the risk of kidney cancer:
An accurate diagnosis may be difficult to establish given that the early stages of renal cancer are asymptomatic. Renal tumours are often discovered incidentally on radiologic imaging performed for an unrelated reason. The prevalence of various radiological imaging procedures such as intravenous pyelography (IVP), ultrasonography, or computed tomography (CT) scanning have revolutionised the way abnormal renal masses are detected for early stage renal cancer in patients who are asymptomatic.
The first steps taken in order to diagnose this condition are observing any of the signs and symptoms, and an anamnesis to evaluate any risk factors. Upon physical examination, palpation of the abdomen may reveal the presence of a mass or an organ enlargement.
Although this disease lacks characterisation in the early stages of tumour development, considerations based on diverse clinical manifestations, as well as resistance to radiation and chemotherapy are important. The main diagnostic tools for detecting renal cell carcinoma are:
The type of treatment depends on multiple factors and the individual, some of which include:
Every form of treatment has both risks and benefits involved, a health care professional will provide the best options that suit the individual circumstances.
Active surveillance or "Watchful waiting" is becoming more common as small renal masses or tumours are being detected and also in the older generation surgery is not always suitable. Active surveillance involves completing various diagnostic procedures, tests and imaging to monitor the progression of the RCC before embarking on a more high risk treatment option like surgery. In the elderly, patients with co-morbidities and in poor surgical candidates, this is especially useful.
Different procedures may be most appropriate, depending on circumstances.
Radical nephrectomy is the removal of the entire affected kidney including Gerota's fascia, the adrenal gland which is on the same side as the affected kidney, and the regional lymph nodes all at the same time. This method although severe is effective. But it is not always appropriate, as it is a major surgery that contains the risk of complication both during and after the surgery and can have a longer recovery time. It is important to note that the other kidney must be fully functional, and this technique is most often used when there is a large tumour present in only one kidney.
Nephron-sparing partial nephrectomy is used when the tumor is small (less than 4 cm in diameter) or when the patient has other medical concerns such as diabetes or hypertension. Partial nephrectomy involves the removal of the affected tissue only, sparing the rest of the kidney, Gerota's fascia and the regional lymph nodes. This allows for more renal preservation as compared to the radical nephrectomy, and this can have positive long term health benefits. Larger and more complex tumors can also be treated with partial nephrectomy by surgeons with a lot of kidney surgery experience.
Laparoscopic nephrectomy uses laparoscopic surgery, with minimally invasive surgical techniques. Commonly referred to as key hole surgery, this surgery does not have the large incisions seen in a classically performed radical or partial nephrectomy, but still successfully removes either all or part of the kidney. Laparoscopic surgery is associated with shorter stays in hospital and quicker recovery time but there are still risks associated with the surgical procedure.
Surgery for metastatic disease: If metastatic disease is present surgical treatment may still a viable option. Radical and partial nephrectomy can still occur, and in some cases if the metastasis is small this can also be surgically removed. This depends on what stage of growth and how far the disease has spread.
Targeted ablative therapies are also known as percutaneous ablative therapies. Although the development of laparoscopic surgical techniques that are used to complete nephrectomies has reduced some of the risks associated with surgery, surgery of any sort in some cases will still not be feasible. For example, the elderly, people already suffering from severe renal dysfunction or people who have several comorbidities surgery of any sort is not warranted. Instead there are targeted therapies which do not involve the removal of any organs or serious surgery. Rather, these therapies involve the ablation of the tumor or the affected area. Ablative treatments use imaging such as computed tomography (CT) or magnetic resonance imaging (MRI) to identify the location of the tumors, which ideally are smaller than 3.5 cm in size and to guide the treatment. However there are some cases where ablation can be used on tumors that are larger.
The two main types of ablation techniques that are used for renal cell carcinoma are radio frequency ablation and cryoablation.
Radio frequency ablation uses an electrode probe which is inserted into the affected tissue, to send radio frequencies to the tissue to generate heat through the friction of water molecules. The heat destroys the tumor tissue. Cell death will generally occur within minutes of being exposed to temperatures of or above 50°C.
Cryoablation also involves the insertion of a probe in to the affected area. However, in this case, instead of heat being used to kill the tumor, cold is. The probe is cooled with chemical fluids which are very cold. The freezing temperatures cause the tumor cells to die by causing osmotic dehydration, which pulls the water out of the cells, destroying the enzyme, organelles, cell membrane and freezing the cytoplasm.
Chemotherapy and radiotherapy are not as successful in the case of RCC. RCC is resistant in most cases but there is about a 4-5% success rate sometimes, but this is often short lived with more tumours and growths developing later.
Cancer vaccines are being developed, but so far have been found to be effective for only certain forms of the RCC. The vaccines are being designed to "prime" the immune system to provide tumour specific immunity. They are still being developed and present another treatment possibility.